I am using the free version of Zoho Docs and trying to upload a file into the root folder using PHP and the Docs API.

My source code is as below:

1. <?php
2. $cipher = 'rsa_aes_128_sha';
3. $AUTHTOKEN=" .... ";
4. $path=" ... ";
5. $filename=" ... ";
6. 
   
7. $url = "https://apidocs.zoho.com/files/v1/upload?authtoken=".$AUTHTOKEN."&scope=docsapi";
8. 
   
9. $fields = array(
10.             'filename' => $filename,
11.             'content' => file_get_contents($path."/".$filename)
12.         );
13. 
    
14. $ch = curl_init();
15. 
    
16. $query = http_build_query($fields);
17. 
    
18. curl_setopt($ch, CURLOPT_POST, TRUE);
19. curl_setopt($ch, CURLOPT_POSTFIELDS, $query);
20. curl_setopt($ch, CURLOPT_URL, $url);
21. curl_setopt($ch, CURLOPT_SSL_CIPHER_LIST, $cipher);
22. curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
23. 
    
24. $result .= curl_exec($ch);
25. echo $result;
26. curl_close($ch);
27. ?>

The result is sometimes a properly formed response which says 'Invalid URL' and sometimes a bizarre string that just says:

1. <!--$Id$ -->

The URL format appears to match that shown in the API specification. There are some other possible parameters, but these are clearly stated to be optional.

I have checked that the filename and path are correct, the file has proper permissions and the file contents are being read okay, and query string being constructed properly. The file size is well under the maximum 100M. Other Docs API functions work okay with the same AuthToken.

What might be going wrong with the file upload?